The present invention relates to a storage system, and an access path state update method.
Availability can be improved in a storage system by making a plurality of access paths redundant, since even if one access path fails, the path can be switched to another access path and continue communication. Furthermore the I/O can be faster if a band is widened by using a plurality of access paths for an I/O.
Patent Publication JP-A-2000-348005 discloses a storage system which makes paths redundant using access paths having different characteristics. The system uses an SAN (Storage Area Network) as the I/O during normal time use, and uses a LAN (Local Area Network) when a failure occurs to the SAN. Patent Publication JP-A-2007-287064 discloses a storage system which determines an access path to be used, out of a plurality of access paths, according to the performance information and predefined policy. Further, Patent Publication JP-A-2007-94681 discloses a storage system which issues a license key for enabling a port that is not in use, according to the utilization factors of the access paths and occurrence of failure, and switches the current path to the enabled access path.
In the case of the system disclosed in Patent Publication JP-A-2000-348005, a SAN is used for the operating system, and a LAN is used for the standby system, an I/O is issued for only one of these, and the load conditions are not considered. In the case of the system disclosed in Patent Publication JP-A-2007-287064, an access path to be used can be determined by periodically checking the operation state of the access paths, but the quick handling of an occurrence of a failure is not considered. In the case of the system disclosed in Patent Publication JP-A-2007-94681, a management server for managing the license is essential, and processing to enable and disable the access paths is generated, which makes the configuration complicated.